Socio-cultural factors of teachers’ conceptions of knowledge: epistemic beliefs of Arab teachers     

Mohamed Taha Mohamed 《Teacher Development》2014,18(1):46-64

This research investigates aspects of epistemic beliefs of pre-service and in-service teachers in the United Arab Emirates, and how these beliefs might be related to factors such as teachers’ gender, location (where they live), and the subject they teach (humanities vs. science). A standardized Arabic version of the Epistemic Belief Inventory was administered to a group of 35 pre-service teachers and 52 in-service teachers. The results indicated that in-service teachers had more sophisticated beliefs than pre-service teachers on Certainty of Knowledge, Omniscient Authority, and Innate Ability dimensions. Also, male teachers were found to be less sophisticated than female teachers and teachers from rural areas tended to think in a simpler way than teachers from urban areas. Although there was no main effect of subject, it significantly modified the effects of gender and location. The data showed the multidimensional nature of epistemic beliefs, and were discussed in the context of Arab/Emirati culture.  相似文献   

Comparison of the Carcinogenic Potential of Smokeless Tobacco and Smoked Tobacco by Quantifying the Excretion of Nicotine Metabolite NNAL in Patients with Oral Leukoplakia     

S. Mohamed Anser  Nalini Aswath 《Indian journal of clinical biochemistry : IJCB》2014,29(2):246-249

The case control study was conducted to quantify the amount of the carcinogenic tobacco specific nitrosamine in smokeless tobacco users and smokers in patients with oral leukoplakia and also to emphasize the role of tobacco-specific nitrosamine in the incidence of oral leukoplakia. The study was conducted on 30 patients. The urine samples were obtained from smokeless tobacco users with oral leukoplakia, smokers with oral leukoplakia and non-tobacco users (i.e. people who do not use tobacco in any form). The collected samples were processed by gas chromatography-mass spectrometry. A highly significant difference of NNAL[4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol] in smokeless tobacco users than tobacco smokers P = 0.0002 (Table 1) was obtained. This significant difference shows smokeless tobacco is more carcinogenic than smoked tobacco. This study confirmed that NNAL is a potent biomarker for calculating the risk of occurrence of carcinoma in smokeless tobacco users and smokers, and that smokeless tobacco is more harmful than smoked tobacco.  相似文献   

Hybrid sliding mode observer for switched linear systems with unknown inputs     

Jeremy Van Gorp  Michael Defoort  Kalyana C. Veluvolu  Mohamed Djemai 《Journal of The Franklin Institute》2014

This paper addresses the state observation and unknown input estimation of a class of switched linear systems with unknown inputs. This class of systems may have modes in which the state is not fully observable. A state transformation allows implementing two suitable reduced-order observers. The first one, based on second order sliding mode techniques, is proposed to reconstruct the discrete state in the presence of unknown inputs. The second one, based on gathering partial information from individual modes of the switched system and on higher order sliding mode techniques, is introduced to estimate the continuous state. Then, the observer injection signal of the first second order sliding mode observer is used to estimate the unknown inputs. Simulation results highlight the efficiency of the proposed method.  相似文献   

Analysis of adaptive detection of moderately fluctuating radar targets in target multiplicity environments     

Mohamed B. El Mashade 《Journal of The Franklin Institute》2011,348(6):941-972

In this article, we provide a complete detection analysis, in its exact form, of what is known as moderately fluctuating radar targets when the background environment contains a number of interfering targets along with the target under test. The illumination of this class of radar targets by a coherent pulse train, return a train of correlated pulses with a correlation coefficient in the range 0<ρ<1 (intermediate between SWII and SWI models). Since the adaptive detection is one of the desirable features for modern radar receivers, it becomes of importance to adaptively detect this class of targets. The attractive class of adaptive detectors is that based on order-statistics (OS) technique. The more advanced version of the OS algorithm, known as the generalized trimmed-mean (GTM) scheme, is chosen here to carry out this task. It implements trimmed averaging of a weighted ordered range samples. This processor is analyzed for the case where the radar receiver incorporates a postdetection integrator amongst its contents and where the operating environment is multitarget. The primary and the secondary interfering targets are assumed to be fluctuating in accordance with partially correlated χ² fluctuation model. SWI and SWII well-known models represent the cases where the signal is completely correlated and completely decorrelated, respectively, from pulse to pulse. It is shown that the processor performance improves, for weak SNR of the primary target, as the correlation coefficient ρ_s increases and this occurs either in the absence or in the presence of spurious targets. For strong SNR, on the other hand, the processor performance degrades as ρ_s increases and the SWI and SWII models enclose the correlated target case and this behavior is common for all GTM based schemes.  相似文献   

Preparing teachers for a mobile world,to improve access to education     

Mohamed Ally  Margarete Grimus  Martin Ebner 《Prospects》2014,44(1):43-59

Recent statistics on the use of mobile technology proclaim that the world is becoming mobile. People use their phones to socialize, to conduct business, to search for information, and more. For the first time in history, people around the world have the potential to learn from any location at their own convenience. But first, education systems must change, to facilitate mobile access to education. As this article describes, the most important change will be training teachers, both in pre-service programmes and through professional development, to use the technology to design and deliver education and to create bridges to informal learning. The article also describes some projects around the world that are helping to prepare teachers for the mobile world, and some pilot projects using the technology. Most such research, however, is limited to short-term studies focusing on learners’ satisfaction with mobile learning. Future studies must consider its long-term benefits and its impacts on performance and retention. As mobile technologies emerge, teachers have to keep up with the changes so that they can take advantage of the power of the technology to design and deliver education.  相似文献   

A self-contained polymeric cartridge for automated biological sample preparation     

Xu G  Lee DY  Xie H  Chiew D  Hsieh TM  Ali EM  Lun Looi X  Li MH  Ying JY 《Biomicrofluidics》2011,5(3):34107-341079

Sample preparation is one of the most crucial processes for nucleic acids based disease diagnosis. Several steps are required for nucleic acids extraction, impurity washes, and DNA/RNA elution. Careful sample preparation is vital to the obtaining of reliable diagnosis, especially with low copies of pathogens and cells. This paper describes a low-cost, disposable lab cartridge for automatic sample preparation, which is capable of handling flexible sample volumes of 10 μl to 1 ml. This plastic cartridge contains all the necessary reagents for pathogen and cell lysis, DNA/RNA extraction, impurity washes, DNA/RNA elution and waste processing in a completely sealed cartridge. The entire sample preparation processes are automatically conducted within the cartridge on a desktop unit using a pneumatic fluid manipulation approach. Reagents transportation is achieved with a combination of push and pull forces (with compressed air and vacuum, respectively), which are connected to the pneumatic inlets at the bottom of the cartridge. These pneumatic forces are regulated by pinch valve manifold and two pneumatic syringe pumps within the desktop unit. The performance of this pneumatic reagent delivery method was examined. We have demonstrated the capability of the on-cartridge RNA extraction and cancer-specific gene amplification from 10 copies of MCF-7 breast cancer cells. The on-cartridge DNA recovery efficiency was 54-63%, which was comparable to or better than the conventional manual approach using silica spin column. The lab cartridge would be suitable for integration with lab-chip real-time polymerase chain reaction devices in providing a portable system for decentralized disease diagnosis.  相似文献   

Multidimensional model to assess the readiness of Saudi Arabia to implement evidence based child maltreatment prevention programs at a large scale     

Maha A. Almuneef  Mohamed Qayad  Ismail K. Noor  Majid A. Al-Eissa  Fadia S. AlBuhairan  Sarah Inam  Christopher Mikton 《Child abuse & neglect》2014

There has been increased awareness of child maltreatment in Saudi Arabia recently. This study assessed the readiness for implementing large-scale evidence-based child maltreatment prevention programs in Saudi Arabia. Key informants, who were key decision makers and senior managers in the field of child maltreatment, were invited to participate in the study. A multidimensional tool, developed by WHO and collaborators from several middle and low income countries, was used to assess 10 dimensions of readiness. A group of experts also gave an objective assessment of the 10 dimensions and key informants’ and experts’ scores were compared. On a scale of 100, the key informants gave a readiness score of 43% for Saudi Arabia to implement large-scale, evidence-based CM prevention programs, and experts gave an overall readiness score of 40%. Both the key informants and experts agreed that 4 of the dimensions (attitudes toward child maltreatment prevention, institutional links and resources, material resources, and human and technical resources) had low readiness scores (<5) each and three dimensions (knowledge of child maltreatment prevention, scientific data on child maltreatment prevention, and will to address child maltreatment problem) had high readiness scores (≥5) each. There was significant disagreement between key informants and experts on the remaining 3 dimensions. Overall, Saudi Arabia has a moderate/fair readiness to implement large-scale child maltreatment prevention programs. Capacity building; strengthening of material resources; and improving institutional links, collaborations, and attitudes toward the child maltreatment problem are required to improve the country's readiness to implement such programs.  相似文献   

一种车联网多跳视频传输实验系统的设计与实现(英文)     

默罕莫德·默森  许凯凯  刘诚毅  沈连丰 《东南大学学报》2014,(4):403-410

提出一种在车辆自组织网络(VANET)中应用的无线多跳视频传输实验系统的设计和实现方案及其对应的传输控制和路由选择协议.该系统将嵌入式Linux与IEEE 802.11n传输协议集成到ARM内核,由S3C6410主控模块、无线局域网网卡及LCD屏等构成.针对VANET的无线多跳视频传输场景,对视频编译码分别采用H.264和JPEG两种标准实现并对它们的压缩比、时延、传输丢包率等性能进行了理论分析和实验比较,进行了室内室外多种不同场景的实际测试.结果表明:所设计的多跳视频传输实验系统方案能够适应VANET等多种场景的应用,所提出的传输控制和路由选择协议能够保证视频传输的多跳和实时性要求.  相似文献   

Developing anti-discriminatory education: the impact of specialist training on practitioners and pupils     

Carmen Mohamed 《Education 3-13》2013,41(2):143-151

This article addresses the question as to whether training pre-school practitioners in an approach to anti-discriminatory education can impact on the developing attitudes of young children. This article attempts to analyse the effect of training practitioners in the delivery of an anti-discriminatory curriculum on the developing attitudes of the children they are teaching. This training was carried out with Leicestershire Foundation Stage settings.  相似文献   

Monitoring Coagulation Proteins During Progression of Liver Disease     

Mohamed Hessien  Mohamed Ayad  Wafaa M. Ibrahim  Batoul Izz ulArab 《Indian journal of clinical biochemistry : IJCB》2015,30(2):210-216

This work was designated to monitor the coagulation abnormalities associated with the gradual progression of liver diseases. The study included fifty patients; forty were diagnosed with liver cirrhosis with different stages categorized according to the Childs-Pugh classification and another ten patients were diagnosed with hepatocellular carcinoma (HCC). Haemostatic variables including fibrinogen (FI), calcium (FIV), transglutaminase (FXIII), prothrombin time (PT) and platelet count were estimated in patients and compared with the baseline levels of healthy subjects (n = 10). The results demonstrated that the fibrinogen level was progressively decreased, whereas PT was progressively prolonged in Child A, Child B and Child C groups. The maximum deterioration was observed in HCC patients. Calcium significantly increased in mild (Child A) and moderate (Child B) but not in Child C cirrhosis and HCC patients. FXIII level did not show any significant changes in cirrhotic patients compared to healthy group. Some of the haemostatic variables we investigated were correlated with serum albumin and bilirubin but not with aminotransferases (ALT and AST). The results indicated that the haemostatic abnormalities in fibrinogen, calcium and PT (but not FXIII) were deteriorated in parallel with the gradual regression of the constitutional function of liver.  相似文献